Process for scouring vegetable fibers, &amp;c.



XH lyi lll flc- 1 1 UNITED :STATES ROSS REFEQZF ITIZ PATENT EMILE THEODORE JOSEPH WATREMEZ, 0F AVILLY, PAR S ENLIS, FRANCE,

PROCESS FOR SCOURING VEGETABLE FIBERS, &C.

' No Drawing.

and useful Process for Scouring Vegetable Fibers, &c., which improvements are fully set forth in the following specification.

The process according to the present invention is based on the use in scourin baths consisting essentially in a mixture of alkali or alkaline salt, metallic oxid and a hypochlorite such as J avelle water. The metallic oxid may be replaced-if desired,j by the metal itself reducedto powder. Any metal ma lbe'employed, preferably zinc. p

t should beunde rstood that the proportions of the various constituents of the bath maybevaried. ,7

y way" of example, for the treatment of 'cotton fibers the following proportions are preferablyused:+ p V Caustic soda lye of 30? to 35 'Baum strength; 40 liters Javelle water of "commercial stren h. via-16 to 18 Baum 30 liters Into this solution is stirred, in the cold, zinc oxid' 1 kilog.

After two hours stirring, sufficient water is added to make the total volume up to 1000 liters.

The fibers to be treated are steeped with the bath liquor by means of pressure rollers. As soon "as they are uniformly steeped, they are preferably placed in a keir into which the bath liquor is pumped until the fibers are completely covered,

The fibers are kept immersed in the bath during a period of 12 to 24 hours and even longer, the time varying with the nature of the product.

The characteristic feature of the bath as described above consists in its composition, that is to say the ,mixture of an alkalimetal hypochlorite and a salt of an alkali metal.

The treatment of the fibers with these roducts if used separately and not in conunction in the same bath would not give any satisfactory result.

When the fibers are lifted from the bath they are rinsed and at once placed in an acid bath consisting, for example of two parts per thousand (by volume) of sulfuric Specification ofLetters Patent.

Patented Man 1, 1921.

Application filed October 29, 1919. Serial No..334,3 45.

heated nearly to boiling point.

The fibers are treated for'several minutes acid of Baum strength, which is and are then rinsed again, being afterward subjected to the bleaching process proper.

In certain cases the action of the original bath is so powerful that no subsequent bleaching is necessary, the libersafter the 1 second above-mentioned rinsing,=being suffi-, ciently bleached for industrial use."

- When the fibersare very diflicultlto scour and bleach the operation may be repeated several times without any danger, 'to' the fibers, with or without a bleaching operation, 'between two consecutive scourings, that is to sayfor instance, on leaving the acid bath the fibers ar'e treated. with ,.-a hypochlorite in theord inary apparatus 'and are SEARCH ROOM then returned to the original bath. The..

fibers maybe passed throughthe original bath several times. n

If instead of working in the cold it is preferred to treat the fibers in a boiling hot bath, the composition of modified as follows on the other hand. In this latter 'casecthe Y alkali is added to the already existingmizrture. B .wa of example, iflzincis utilized as thei'edu ing metalthe following pro ortions may be used for treating 1000 ki ogs. of material Sodium thiosulfate (Na s O 25 kilogs. is dissolved in commercial Javelle water 50 liters. Zinc powder 5 kilogs. is then stirred into the solution, which is left standing for 12 hours. Caustic soda lye of 30 Baum 150 liters is added and after stirring, the mixture is left standing for 24 hours.

The unattacked zinc particles rapidly subside after agitation of the mass which is decanted but should not he filtered. In this way a mixture is obtained of entirely different appearance and properties from that obtained by simply treating the metal with an alkali.

These proportions and qualities may of the bath may be y '80 The bath is preparedf by I treatingthe' course be varied according to the nature of the fibers to be treated and the effect which it is desired to obtain. .7 This. mixture. is diluted with Water in order'to bring the bath to the desired vol ume and is then heated to boiling point.

, The bath has a tendency to become neutral by reason of the intense action on the natural coloring matters. It is necessary to Watch it and to add, if necessary, caustic soda in small quantities, in order to maintain the alkalinity.

Boiling is prolonged for 4 to 6 hours. Then, 1n order to attain a still more complete scouring, the combined substances existing in the fiber are precipitated by adding 15 kilo s. of slaked lime and by continuing the boiling for 3 to 4 hours.

It should be noted that on the one hand the complete. removal of the precipitated substances is indispensable and that on the other hand, the compounds with ammonia as the base are the most easily attacked.

Before the acid treatment described below, the fibers are immersed for 2 to 3 hours in a bath containing, for example 5 to 7 per cent, by volume, of ammonium sul- 'fate. After rinsing-they are immersed for 2 to 4 hours in a coldvacid bath consisting for instance of 2 'per' cent. by volume of sulfuric acid of"60 Baum strength.

Thereupon the fiber is rinsed and is then ready for rapid and complete bleaching by the ordinary means.

The bath is so effective that in certain cases the operation can even be performed in the cold, but in such case it is preferable to pass the fiber after a summary rinsing, throughmilk of lime. This allows the first bath to be preserved, all that is necessary being to replenish it.

be applied to any treatment based on the use of a soluble salt of an alkali-metal salt in order to effect the scouring.

Iclaimasmy inventions 1. A process for scouring fibers of vegetable origin With-the object of facilitating and accelerating their final bleaching, characterized by the feature that the fibers to be treated are immersed in the cold in a bath consisting ofamixture of an alkalija metallic oxid and an alkali metal hypochlorite, for a time varying from 12 to 24 hours, thereupon rinsed, treated in the warm for several minutes with sulfuric acid solution and finally rinsed.

2. A process ofjscou rin'g' vegetable fibers, consisting in steeping the'fibers in a bath comprising an alkali, a metallic substance and an alkalinietal hypochlorite; then successively rinsing the fibers, treating thenr with sulfuric acid solution and again rinsing them. Q .1,

3. A process of scouringve'getables fibers,

consisting in steeping the: fibers, in I a bath comprising an a1kali, lavelle; water and mm; and thensuccessivelynnsrn'gfthe fibers, treatingthem eWltll SUllfl lIlC acid solution and again rinsing'them.

4.-. A process of'scouring vegetable fibers,

consisting in steeping; the fibersiinla bath comprising an alkali, Javelle zinc; and then'rinsing the fibers; p

The herein-disclosed p'ro'cess'of scouring vegetable fibers, which consists in dissolving a soluble alkali metal hypochlorite in a soluble alkaline reducing salt, and then subjecting a metal to the action ofthe solution thus obtained; then steeping the fibers in the solution obtained from theaction of the first solution on rinsing the fibers.

In testimony whereof I have signed specification in the presence of twosnbscribing witnesses.

water; and

the metal; and then Y EMILE THEODORE Josue wartime:

Witnesses: PIcoco'R, Grms. Pnnss'mnj 

